Facebook is restricting employee travel to China, while other big companies including Nissan Motor and Starbucks are taking measures to shield employees in areas hardest hit by a deadly viral outbreak.

The social media network’s employees based in China, and those who recently returned from trips to the country, are also being told to work from home, people familiar with the matter said, asking not to be identified discussing private communications.

As of January 28 Facebook are halting non-essential travel to China by all Facebook employees, said the person, adding that if workers have to visit the country, they will need specific approval. The company declined to comment.

Starbucks, is the most exposed U.S. restaurant chain operating in China, as measured by percentage of worldwide revenue and operating income, according to Guggenheim analyst Matthew DiFrisco. The Seattle-based chain, with about 4,100 cafes in China, said that it’s closing some locations, without providing more details.

Nissan plans to evacuate most of its expatriates and their family members from Wuhan using a chartered plane dispatched by the Japanese government, a company spokeswoman said in an email.